isp1181 NXP Semiconductors, isp1181 Datasheet - Page 23

• Manufacturer Part Number: isp1181
• Description: Isp1181 Full-speed Universal Serial Bus Interface Device
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 08938
Product data
11.2 Resume conditions
11.3 Control bits in suspend and resume
Wake-up from ‘suspend’ state is initiated either by the USB host or by the application:
The steps of a wake-up sequence are as follows:
Table 13:
Register
Interrupt
Interrupt Enable
Mode
Hardware
Configuration
Unlock
•
•
1. The internal oscillator and the PLL multiplier are re-enabled. When stabilized, the
2. The SUSPEND output is de-asserted and the RESUME bit in the Interrupt
3. Maximum 15 ms after starting the wake-up sequence the ISP1181 resumes its
4. In case of a remote wake-up ISP1181 drives a K-state on the USB bus for 10 ms.
5. Following the de-assertion of output SUSPEND, the application restores itself
6. After wake-up the internal registers of ISP1181 are write-protected to prevent
USB host: drives a K-state on the USB bus (global resume)
Application: remote wake-up via a HIGH level on input WAKEUP or a LOW level
on input CS (if enabled via bit WKUPCS in the Hardware Configuration Register).
clock signals are routed to all internal circuits of the ISP1181.
Register is set. This will generate an interrupt if bit IERESUME in the Interrupt
Enable Register is set.
normal functionality.
and other system components to normal operating mode.
corruption by inadvertent writing during power-up of external components. The
firmware must send an Unlock Device command to the ISP1181 to restore its full
functionality. See
Summary of control bits
Rev. 04 — 30 October 2001
Section 12.3.2
Bit
SUSPND
BUSTATUS
IESUSP
SOFTCT
GOSUSP
EXTPUL
WKUPCS
PWROFF
all
for more details.
Function
a transition from ‘awake’ to ‘suspend’ state was
detected
monitors USB bus status (logic 1 = suspend);
used when interrupt is serviced
enables output INT to signal ‘suspend’ state
enables SoftConnect pull-up resistor to USB bus
a HIGH-to-LOW transition enables ‘suspend’
state
selects internal (SoftConnect) or external pull-up
resistor
enables wake-up on LOW level of input CS
selects powered-off mode during ‘suspend’ state
sending data AA37H unlocks the internal
registers for writing after a ‘resume’
© Koninklijke Philips Electronics N.V. 2001. All rights reserved.
Full-speed USB interface
ISP1181
23 of 71